Morris Minor Owners Club

Anyone else experienced this?
In short, it seems that one of the offside shackle plates failed last year, and fell off the car. At some point the other one on that side also failed and fell off. Today, while lifting the car to adjust the rear brakes, I heard something fall, and saw a shackle plate on the floor under the n/s rear spring. All are fractured and broken, though I've only got 3 of them.

They are about 7 years old. Comparing them to an old set of shackle plates, the metal is thinner, perhaps ⅔ to ¾ of the thickness of the old ones. I'd imagine one has failed, and the misalignment that results has caused the others to fail one by one.

Shackle plate failure has been discussed on here before - approx. 18 months ago.

The shackle plate as shown in the link below has the side return lip extended past the shackle pin hole not like the ones that have failed.

http://www.morrisminorspares.com/rear-s ... de-p831375

The genuine BMC shackle plates as fitted to my Minor are similar to the ESM item.

I will get the metal thickness of those BMC plates in the morning.

I would suggest that you use the ESM type shackle plates and fit shackle pins with UNF threads as the shoulders fitting against the shackle plate are better finished than those with the original BSF thread and therefore produces less strain/loading on the shackle plate.

Just measured the new ones and the old ones. The new plates that failed are 2.1mm, the old ones are 3.1mm, so the old ones, original items now nearly 50 yrs old, are 50% thicker.
I will refit the old ones temporarily, as I need the car for a couple of short runs at the weekend. I'll order new ones as suggested.

I have checked the thickness of a BMC shackle pin plate fitted to my Minor and it measures 3.15mm.

At 2.1mm and with no extension of the rolled edge past the shackle pin hole no wonder it failed.
There is quite a lot of side loading on these shackle pin plates.

Ok, a picture says a thousand words.
The top 3 are the remaining shackle plates that have failed, one having gone AWOL without my knowledge. The bottom one is one of the original BMC plates.

Neil
Many thanks for posting the photos above.
60mm is the correct distance between the shackle pin centres.

The 85.35mm between shackle pin centres is incorrect and will put more loading onto the shackle plates.
Phil

I should add that I have telescopic rear dampers fitted, in turrets.

The type of damper fitted should have no bearing on the type or failure of the shackle pin plates.

I have tele dampers fitted to the rear of my Minor which are not fitted into turrets.

I hope our good Minor parts suppliers will be made aware of this, bearing in mind the implications of product liability. I shall certainly be checking that none on mine are only 2mm thick. I’ve also seen these plates made considerably thinner and weaker by rust pitting.

this happened on a dual carriageway in my A30 at 60mph. it frightened the life out of me. I had to lip home at 20mph (not hard in an A30). last September I replaced all the rear suspension and hopefully that should out live me now.

if it was mine i'd be looking at the crack in the body as well,or are you already on the job.

if it was mine i'd be looking at the crack in the body as well,or are you already on the job.